Are your ethos supposed to change? I didn't notice that happening, though since I am running massive amounts of ethics divergence I can't really go back and check.
I can't for the life of me find where the game defines the portrait change- I do know its there, though, and it seems predictable.
Every Arthropoid I've played through with has become the "beetle" portrait. For the plantoids, the portrait I initially ascribed to them was a mistake- I misremembered from an AAR and upon checking back, their experience lines up with yours (which means at least two people have experienced their plantoids becoming the same portrait).
Humanoids have all been reported to become the most "alien" of the humanoid portraits.
Currently the only disparity I've seen is what @SoundwaveUK experienced- what he changed into is the portrait that the person who documented the entire event chain started as, but my suspicion is that it might not give you a different one in that event normally (see: @smjjames remaining as the "feather dragons"). I'm not sure about that one, really- if his POPs didn't get an Ethos change as part of the event chain, he might have had a bug.
No wonder I couldn't find it- I didn't expect a DLC to overwrite vanilla files.The code for the portrait change is in "00_scripted_exents.txt". In it, the exact portrait changes are:
Arthropoid (all but #11) -> Arthropoid #11
Arthropoid #11 -> Arthropoid #10
Mammalian (all but #10) -> Mammalian #10
Mammalian #10 -> Mammalian #13
Fungoid (all but #12) -> Fungoid #12
Fungoid #12 -> Fungoid #10
Humanoid (all but #4) -> Humanoid #4
Humanoid #4 -> Humanoid #3
Molluscoid (all but #11) -> Molluscoid #11
Molluscoid #11 -> Molluscoid #12
Plantoid (all but #15) -> Plantoid #15
Plantoid #15 -> Plantoid #10
Reptilian (all but #8) -> Reptilian #8
Reptilian #8 -> Reptilian #4
Avians do not change portraits.
The Messenger Unleashed event, if allowed to happen, changes the Ethos of all your converted POPs.Are your ethos supposed to change? I didn't notice that happening, though since I am running massive amounts of ethics divergence I can't really go back and check.